Understanding how SLTs work
February 7, 2007
When you make an System Load Tape (SLT), are you adding anything to the tape? That is, are you specifying extra files be stored?
Mike Hornsby replies:
The SLT should have everything required to accomplish the first four steps of a system INSTALL:.
1. Boot from Alternate Path to ISL
2. Install MPE/iX to the Primary Path
3. Restore @[email protected],@[email protected], & all diagnostics
4. Reboot to ISL and START.
Notes from experience over time:
A. It is also very important to also have the HP Factory media handy. Some bugs in the past created SLT tapes that would validate but were non-functional. And, it is possible that disk errors or more frequently patch errors can result in a series of SLTs that have latent problems. These HP Factory media should be stored in a safe place with a note on the console with a clue to where this safe place is.
B. It is very common for SLTs to play hide and seek. It is not at all amusing to play this game at 2:30 AM. It is a good idea to have multiple copies, one stored in a safe place and another physically attach to the system in a folder/envelope that also contains a SYSGEN or better yet a SYSINFO configuration listing. If the stable storage is lost due to a replacement of a processor or main board, establishing the correct alternate and primary boot paths from the configuration listing is preferable to the trial and error method.
C. If you have disk arrays, it is a good idea to have a separate dedicated console (if applicable) and have the MPE/iX-based diagnostics (if applicable) included in the SLT tape. These arrays work very well, until they don’t. The host-based diagnostics usually have a more comprehensive command set, and are far easier to use than the array front panel or direct connected console.
D. If you have a CD attached to the system, it is a good idea to acquire the the HP diagnostics CD and keep it physically attached to the system. The CD can load the Offline Diagnostic Environment (ODE) at least 100 times faster than the SLT tape. [Ed. Note: Hornsby suggested the HP Software Depot site as a source of the ODE CD, but our check tonight seems to show only HP-UX versions of the CD. On the other hand, maybe it doesn't make any difference; so much of the PA-RISC server hardware on 3000 and 9000 sides are identical.]
Hornsby also added a plug for Beechglen’s support services, which test "all of our customer’s SLTs and a full disaster recover test. It is one thing to think that you have all the necessary components. It is much better to have an independent party perform a complete end to end test."